GB2190121A

GB2190121A - Shovel for an excavator

Info

Publication number: GB2190121A
Application number: GB08707966A
Authority: GB
Inventors: Dieter Schwappach
Original assignee: O&K Orenstein and Koppel GmbH
Current assignee: CNH Industrial Baumaschinen GmbH
Priority date: 1986-04-05
Filing date: 1987-04-03
Publication date: 1987-11-11
Anticipated expiration: 2007-04-03
Also published as: GB8707966D0; JPS62236928A; GB2190121B; DE3611493A1; US4748754A; IT8747540A0; DE3611493C2; FR2596785A1; FR2596785B1; IT1205711B

Description

GB 2 190 121 A 1 SPECIFICATION occurring during operation, with the result

that the cutting edge plates would fall off the shovel edge.

Shovel for an excavator The problem with which the present invention is concerned is that of providing an arrangement which The invention relates to a shovel for an excavator. 70 will allow edge caps to be secured, simply, reliably The invention is particularly concerned with the and with safetyto an excavator shovel and in such a provision of replaceable members on the digging mannerthatthey can be replaced. More particularly, edge of an excavator shovel, especiallyforthe for an excavatorshovel having spaced-apart teeth on purpose of protecting the digging edge againstwear. the digging edge, the invention is concerned with The digging edge of the shovel of an excavator 75 enabling edge caps to be replaced irrespective of the (which shovel may also be described as a scoop, design and method of fastening of the tooth tips and, according to its shape) can be provided with above all, without mechanical weakening of the projecting teeth. These teeth may comprise tooth shovel wall by holes for receiving the cap-securing retainers which are secured to the edge of the shovel means.

at a distance apart from one another and tooth tips, 80 The present invention provides a shovel for an made of a highly wear-resistant material, which are excavator, on the digging edge of which is located at attached to the tooth retainers in such a mannerthat least one cap memberwhich is releasably held, by a they can be replaced. In order also to protectthe securing member, in engagement with a retaining edge of the shovel against wear in the gaps between piece on the shovel, the securing member being a the teeth it is customary (instead of forming a 85 resiliently- compressible memberwhich is located in built-up region of highly wear-resistant material a securing position between opposing surfaces of which is expensive to replace and can involve the cap member and the retaining piece and which difficulties) to fitthe areas of the shovel edge can be inserted in the securing position in a direction between the teeth with replaceable caps made of a perpendicularto the surface of the shovel.

relatively wear-resistant material. 90 The cap member may have an opening through It is not suitable in practice to secure the caps with which the securing member can be inserted in the screws or other similar fastenings which are pushed securing position. In an embodiment of the through holes in the wall of the shovel because of the invention, the cap member has an extension which great disadvantage that the stability or strength of fits overthe retaining piece and in which the opening the front edge of the shovel, which has to absorb the 95 isformed.

high working forces acting on the teeth, is The securing member may comprise two outer appreciably impaired by the fastening holes. A parts between which is a resiliently-compressible different fastening method, in which the tooth tips intermediate member. The outer parts of the are designed with lateral projections which hold the securing member may be engageable with each caps between the teeth and keep them pressed 100 otherto limitthe extent to which the intermediate againstthe edge of the shovel, also has member can be compressed. Preferably,the disadvantages. In particular, this method requires securing member is co- operable with at least one of thetooth tipsto be specially designed and italso the opposing surfaces in a mannerwhich resists requiresthatthe capsfitthe spaces between the removal of the securing memberfrom the securing teeth and match thefastening position of thetooth 105 position.

tips on the tooth retainers. Moreover, in orderto The present invention further provides a shovel for replacethe caps,the tooth tips also have to be an excavatonthe digging edge of which shovel has removed from thetooth retainers and, in addition, teeth arranged at a distance apartfrom one another the securing devices between thetooth tips and the and, between theteeth, is equipped with removable tooth retainers have to be removed. 110 caps made of relatively wear- resistant material each An alternative arrangementfor use atthe digging cap having a hook-like extension which engages edge of an excavator shovel is described in US PS underthe edge of the shovel and a leg which fits over 3,995,384. In this arrangement, a plurality of the edge of the shovel and engages a respective replaceable parts, in the form of uniform plates with retaining piece arranged, between teeth, on the top a large width in the direction of the shovel edge, are 115 of the shovel, with the cap and the retaining piece used to provide the shovel with a continuous cutting being held together by a securing memberwhich is edge. The means used with these cutting edge detachably inserted in a securing position between plates, to secu re them against being pulled off the opposing surfaces of the retaining piece and an shovel edge, comprises a securing boltwhich is extension of the cap leg, which extension fits over pushed in (parallel to the uppersurface and front 120 the retaining piece and has a window-like opening edge of the shovel wall) between a retaining member through which the securing member can be inserted on the shovel wall and a co-operating extension of in the securing position in a direction perpendicular the edge plate. Such an arrangement requires there to thetop of the shovel,the securing member to be sufficient room to permitthe insertion of the comprising two outer parts which rest againstthe securing bolt parallel to the surface of the shovel wail 125 opposing surfaces of the retaining piece and the cap and there is also the danger that a securing bolt, leg extension respectively and between which is a wedged between the retaining member and the edge resiliently-compressible intermediate member, at plate extension and secured against longitudinal least one of the outer parts being shaped to engage displacement only byfriction, may become loose the respective opposing surface in a mannerwhich and fallout as a result, for example, of jarring 130 resists removal of the securing memberfrom the 2 GB 2 190 121 A 2 securing position. yoke-like extension 12 in orderto compressthe Ashovel in accordancewith the invention may securing member 11 forthe purpose of removing it.

have, on the digging edge, a projection in the region The leg 7 of the cap is designed with a collar-like of theleach cap, which projection engages in a recess projection 14which covers the retaining piece 9, with inthecap. 70 the resuitthatthe retaining piece 9, which isfixed by In the drawing, which shows an embodiment of welding to the shovel (as already mentioned) and is the invention by way of example: reused when the cap 5 is replaced, is protected Figure 1 is a plan view of a part of the shovel and againstwearfrom excavator material when the Figure2 shows a section along the line 11-11 in shovel is in use.

Figure 1. 75 The leg 7 of the cap can be so designedthat, Secured to the digging front edge 1 of the shovel at between the leg and the retaining piece 9 there is a distance apartfrom one another are tooth retainers also an interengagement which is effective 2 onto which tooth tips 3 are placed in such a manner horizontally, in the plane of the upper surface of the asto be removable. The customarytooth securing shovel, and prevents the cap 5 from being displaced means, indicated at 4, hold the tooth tips 3 on the 80 laterally on the edge 1 of the shovel. In orderto tooth retainers 2. Located in the regions of the shovel intercept anytransverse forces acting on the cap 5 in edge 1 between the shovel teeth, in such a manner the direction of the edge of the shovel, the edge 1 of thatthey can be removed and replaced, are caps 5 the shovel is preferably designed to have a that are relatively resistant to wear. projection 15 which preferably engages in the Each cap 5 has a short hook-like projection 6 which 85 manner of a wedge in a corresponding recess in the engages underthe edge 1 of the shovel and a long cap 5 and, as a result, supports the cap 5 in a leg 7 which fits overthe edge. The leg 7 rests on the positively locking mannerand prevents itfrom being uppersurface 8 of the shovel and supportsthe cap so displaced laterally on the edge of the shovel.

thatit does nottilt round the edge 1 of the shovel In the arrangement shown in the drawing,the when acted upon by upwardly-directed forces. A 90 provision of theyoke- like extension 12Jorming a retaining piece 9foreach cap is secured, bywelding, window-like opening in the leg 7 of the cap 5, makes to the upper surface 8 of the shovel, between the it possible forthe securing member 11 to be located teeth. The leg 7 of the cap is designed with a rib 10 in position, through the leg 7 f rom above, facing the retaining piece 9, which rib engages a comfortably and without hindrance from the shovel matching recess in the retaining piece 9 and with this 95 teeth lying to the side of the cap. As a result of the recess forms a groove and tongue connection which barb-like interengagement of the securing member is assembled as the cap 5 is put in position. As a 11 with the yoke-like extension 12 (for example by result of this connection, which is positively locking means of a projection on the securing member, in a direction perpendicularto the uppersurface 8 of which engages undera projection on theyoke-like the shovel,the leg 7 of the cap is held firmly and 100 extension) the securing members are reliablyfixed prevented from being lifted off or pulled awayfrom againstworking loosefrom their position. As an the uppersurface 8, and the cap 5 is unabletotilt alternative, there could be a similar barb-like around the edge 1 of the shovel even underthe interengagement of the securing member 11 with action of downwardly-directed forces. the retaining member9, instead of theyoke-like Adetachable cap fastening keepsthe leg 7 of the 105 extension 12.

cap and the retaining piece 9 in engagement in the

Claims

direction in which the cap 5 is put in position. The cap CLAIMS fastening

comprises a securing member 11 which can readily be put in position from above,1. A shovel for an excavator, on the digging edge perpendicular to the top 8 of the shovel, between 110 of which is located at least one cap member which is opposing surfaces of the retaining piece 9 and a releasably held, by a securing member, in yoke-like extension 12 of the leg 7 of the cap. The engagement with a retaining piece on the shovel,the yoke-like extension 12 can be pushed away overthe securing member being a resiliently-compressible retaining piece 6 when the cap 5 is placed on the memberwhich is located in a securing position edge 1 of the shovel. 115 between opposing surfaces of the cap memberand The securing member 11 comprisestwo shells the retaining piece and which can be inserted in the with an intermediate layer of rubber and as a result securing position in a direction perpendiculartothe can be compressed resiliently in the direction in surface of the shovel.

which the cap 5 is put in position. The ability of the 2. Ashovel as claimed in claim 1, in which the cap rubber layerto be compressed is limited bythe two 120 member has an opening through which the securing shells coming into contact with each other, in such a member can be inserted in the securing position.

manner that tensile forces acting on the cap 5 cannot 3. Ashovel as claimed in claim 2, in whichthe cap pull apartthe positively locking connection between member has an extension which fits overthe the leg 7 of the cap and the retaining piece 9. By retaining piece and in which the opening is formed.

means of the rubber layer,the securing member 11 125 4. Ashovel as claimed in anyone ofthe can lock itself automatically in the manner of a barb preceding claims, in which the securing member to the yoke-like extension 12 to prevent itself from comprises two outer parts between which is a lifting outfrom between the opposing surfaces of the resilientlycompressible intermediate member.

retaining piece 9 and the yoke-like extension 12. A 5. Ashovel as claimed in anyone of the tool can be inserted into a notch 13 cut into the 130preceding claims, in which the securing member is 3 GB 2 190 121 A 3 co-operable with at least one of the opposing on the shovel by a securing memberwhich is located surfaces in a mannerwhich resists removal of the in a securing position between opposing surfaces of securing memberfrom the securing position. the cap member and the retaining piece, in whichthe 6. A shovel for an excavator, the digging edge of securing member is resiliently-compressible in a which shovel has teeth arranged at a distance apart 70 direction parallel to the surface of the shovel and can from one another and, between the teeth, is be inserted into the securing position in a direction equipped with removable caps made of relatively perpendicular to the surface of the shovel after the wear-resistant material each cap having a hook-like cap member has been located on the digging edge extension which engages underthe edge of the and is in engagementwith the retaining piece.

shovel and a leg which fits overthe edge of the shovel and engages a respective retaining piece arranged, between teeth, on thetop of the shovel, with the cap and the retaining piece being held Printed for Her Majesty's Stationery Office by Croydon Printing Company (1) K) Ltd,9187, D8991685. together by a securing member which is detachably Published by The Patent Office, 25Southampton Buildings, London, WC2A l AY, inserted in a securing position between opposing from which copies maybe obtained.

surfaces of the retaining piece and an extension of the cap leg, which extension fits overthe retaining piece and has a window-like opening through which the securing membercan be inserted in the securing position in a direction perpendicularto thetop of the shovel,the securing member comprising two outer parts which rest againstthe opposing surfaces of the retaining piece and the cap leg extension respectively and between which is a resUiently-compressible intermediate member, at least one of the outer parts being shaped to engage the respective opposing surface in a mannerwhich resists removal of the securing memberfrom the securing position.

7. Ashovel as claimed in anyone of the preceding claims, in which there is a tongue-and-groove connection between the/each cap member and the respective retaining piece.

8. Ashovel as claimed in claim 3 orclaim 6, in which the extension is in the form of a yoke which can be deflected over the retaining piece to enable the capto be put in position on the digging edge of the shovel.

9. Ashovel as claimed in claim 5 or claim 6, in which at least one of the outer parts of the securing member is in barb-like engagement with the respective opposing surface of the retaining piece/cap.

10. Ashovel as claimed in claim 4orclaim 6, in which the outer parts of the securing member are engagea ble with each other to limit the extent to which the intermediate member can be compressed.

11. A shovel as claimed in any of the preceding claims, in which the edge of the shovel has a projection in the region of the/each cap, which projection engages in a recess in the cap.

12. A shovel for an excavator, substantially as described herein with reference to, and as shown in, the accompanying drawing.

Amendmentsto the claims have been filed, and having the following effect:

(a) Claim 1 above has been deleted ortextually amended.

(b) New ortextually amended claims have been filed asfollows:

1. A shovel for an excavator, on the digging edge of which is located at least one cap member which is releasably held in engagement with a retaining piece